AP Physics C Summer Assignment Kinematics 1. A car whose speed is 20 m/s passes a stationary motorcycle which immediately gives chase with a constant acceleration of 2.4 m/s 2 . a. How far will the motorcycle travel before catching the car? b. How fast will it be going at that time? c. How does that compare to the car’s velocity? d. Draw the following graphs for the car: x(t), v(t), a(t). e. Draw the following graphs for the motorcycle: x(t), v(t), a(t). f. Write the equation of motion for the car. g. Write the equation of motion for the motorcycle. 2. A lab cart moves a long a straight horizontal track. The graph describes the relationship between the velocity and time of the cart. a. Indicate every time interval for which speed (magnitude of the velocity) of the cart is decreasing. b. Indicate every time at which the cart is at rest. c. Determine the horizontal position x of the cart at t = 4 s if the cart is located at x0 = when t0 = 0. d. Determine the traveled distance of the cart over 10 s from the beginning. e. Determine the average speed of the cart for this time interval. f. Find the acceleration of the cart during time: 0 s -4 s, 4 s – 8 s, 8 s – 10 s, 10 s – 14 s, 14 s – 16 s, 16 s – 20 s. g. On the axes below, sketch the acceleration graph for the motion of the cart from t = 0 s to t = 20 s.
Kinematics
1. A car whose speed is 20 m/s passes a stationary motorcycle which
immediately gives
chase with a constant acceleration of 2.4 m/s2.
a. How far will the motorcycle travel before catching the
car?
b. How fast will it be going at that time?
c. How does that compare to the car’s velocity?
d. Draw the following graphs for the car: x(t), v(t), a(t).
e. Draw the following graphs for the motorcycle: x(t), v(t),
a(t).
f. Write the equation of motion for the car.
g. Write the equation of motion for the motorcycle.
2. A lab cart moves a long a straight
horizontal track. The graph
the cart.
is decreasing.
which the cart is at rest.
c. Determine the horizontal position x of the cart at t = 4 s if
the cart is located at
x0 = when t0 = 0.
d. Determine the traveled distance of the cart over 10 s from the
beginning.
e. Determine the average speed of the cart for this time
interval.
f. Find the acceleration of the cart during time: 0 s -4 s, 4 s – 8
s, 8 s – 10 s, 10 s –
14 s, 14 s – 16 s, 16 s – 20 s.
g. On the axes below, sketch the acceleration graph for the motion
of the cart
from t = 0 s to t = 20 s.
3. A bus makes three displacements I the following order:
1) 58 mi, 38 east of north
2) 69 mi, 46 west of north; and
3) 75 mi, south-east
a. Draw a clear diagram showing all three displacement vectors with
respect to
horizontal points (north, east, south, and west).
b. Find the X and Y components of displacement D1.
c. Find the X and Y components of displacement D2.
d. Find the X and Y components of displacement D3.
e. Find the magnitude of the resultant vector.
f. Find the direction of the resultant vector.
4. A ball is thrown horizontally from the roof of a building 75 m
tall with a speed of 4.6
m/s.
a. How much later does the ball hit the ground?
b. How far from the building will it land?
c. What is the velocity of the ball just before it hits the
ground?
5. A projectile is fired with an initial speed of 150 m/s at an
angle of 47 above the
horizontal.
b. Determine the maximum height reached by the projectile.
c. Determine the maximum horizontal distance covered by the
projectile.
d. Determine the velocity of the projectile 5 s after firing.
6. A projectile is fired from the edge of a cliff 95 m high with an
initial speed of 50 m/s at
an angle of 37 above the horizontal.
a. Determine the total time in the air.
b. Determine the maximum height reached by the projectile.
c. Determine the maximum horizontal distance covered by the
projectile.
d. Determine the velocity of the projectile just before it hits the
bottom of the
cliff.
Dynamics
1. Two blocks with masses m1 and m2, respectively, are connected by
a light string. Block 1
is placed on an inclined plane which makes an angle θ with the
horizontal. Block 2 is
suspended from a pulley that is attached to the top on the inclined
plane. The
coefficient of kinetic friction between block 1 and the incline is
µ.
a. Block 1 moves up the inclined plane with a constant velocity v.
On the diagram
below show all the applied force on each block.
b. Determine the mass of block 2 that allows block 1 to move up the
incline with a
constant speed.
c. Determine the mass of block 2 that will cause block 1 to
accelerate up the
incline at a constant rate a.
d. The string between the blocks is cut. Determine the acceleration
of block 1.
2. Two masses m1 = 400 g and m2 = 600 g are connected with a light
string which goes
over a frictionless pulley of negligible mass. The system of two
masses is released from
rest.
ii) Calculate the tension force in the string
iii) Calculate the support force in the pivot of the pulley.
3. In the system presented on the diagram, block 2m and block 3m
are connected by a
light string passing over a frictionless pulley. Block 2m is placed
on the surface of a
horizontal table with negligible friction. Present all answers in
terms of m, l, and
fundamental constants.
a. Determine the acceleration of the system after it is released
from rest.
b. Determine the velocity of 3m block just before it hits the
floor.
c. Determine the velocity of 2m block at the edge of the
table.
d. Determine the distance between the blocks after they landed on
the floor.
4. Block M1 is connected to block M2 by a light string that passes
over a frictionless pulley.
Block M1 is placed on a rough horizontal table. The coefficients of
static and kinetic
friction between the surface and block M1 are µs and µk
respectively.
a. On the diagram below show all the applied force on each
block.
b. Determine the minimum value of coefficient of static friction,
which will prevent the
blocks from moving.
An extra mass Δm is placed on the top of block M2, the extra mass
causes the system of
two blocks to accelerate.
D. Determine the tension force in the string.
5. A railroad wagon accelerates from rest. A
small metallic sphere of mass m is suspended
at the end of a light string which attached to
the wagon’s ceiling and makes an angle θ
with the vertical.
a. On the diagram to the right, draw a free-body diagram of the
sphere.
The wagon accelerates for a total 30 s and reaches a velocity of 15
m/s.
b. Determine the acceleration of the wagon.
c. Determine the angle θ between the string and the vertical during
the acceleration of
the wagon.
6. An 80 kg passenger stands on a measuring scale in an elevator.
The scale reading for the
first 20 s are presented by the graph below. Use g = 10 m/s2 in the
following
calculations.
a. Calculate the acceleration of the elevator for the following
time intervals:
0 – 5 s; 5 – 10 s; 10 – 15 s; 15 – 20 s.
b. Calculate the velocity of the elevator at the end of the
following time intervals:
0 – 5 s; 5 – 10 s; 10 – 15 s; 15 – 20 s.
c. Calculate the displacement of the elevator from the starting
point to the end of the
following time intervals: 0 – 5 s; 5 – 10 s; 10 – 15 s; 15 – 20
s.
d. Draw the following graphs: a(t), v(t), x(t).
Circular Motion 1. A curve with a radius of 50 m is banked at an
angle of
25. The coefficient of static friction between the tires and the
roadway is 0.3. a. Find the correct speed of an automobile that
does
not require any friction force to prevent skidding.
b. What is the maximum speed the automobile can have before sliding
up the banking?
c. What is the minimum speed the automobile can have before sliding
down the
banking?
2. A ball of mass M attached to a string of length L moves in a
circle in a vertical plane as shown above. At the top of the
circular path, the tension in the string is twice the weight of the
ball. At the bottom, the ball just clears the ground. Air
resistance is negligible. Express all answers in terms of M, L, and
g.
a. Determine the magnitude and direction of the net force on the
ball when it is at the
top.
b. Determine the speed vo of the ball at the top. After a few
circles, the string breaks when the ball is at the highest point.
c. Determine the time it takes the ball to reach the ground.
d. Determine the horizontal distance the ball travels before
hitting the ground.
3. A ball of mass M is attached to a string of length R and
negligible mass. The ball moves clockwise in a vertical circle, as
shown above. When the ball is at point P, the string is horizontal.
Point Q is at the bottom of the circle and point Z is at the top of
the circle. Air resistance is negligible. Express all algebraic
answers in terms of the given quantities and fundamental constants.
a. On the figures below, draw and label all the forces exerted on
the ball
when it is at points P and Q, respectively.
b. Derive an expression for vmin the minimum speed the ball can
have at point Z without leaving the circular path.
c. The maximum tension the string can have without breaking is Tmax
Derive an expression for vmax, the maximum speed the ball can have
at point Q without breaking the string.
d. Suppose that the string breaks at the instant the ball is at
point P. Describe the motion of the ball immediately after the
string breaks.
4. A 0.10-kilogram solid rubber ball is attached to the end of an
0.80-meter length of light
thread. The ball is swung in a vertical circle, as shown in the
diagram above. Point P, the lowest point of the circle, is 0.20
meter above the floor. The speed of the ball at the top of the
circle is 6.0 meters per second, and the total energy of the ball
is kept constant. a. Determine the total energy of the ball, using
the floor as the zero point for
gravitational potential energy.
b. Determine the speed of the ball at point P, the lowest point of
the circle.
c. Determine the tension in the thread at i. the top of the
circle;
ii. the bottom of the circle.
The ball only reaches the top of the circle once before the thread
breaks when the ball is at the lowest point of the circle. d.
Determine the horizontal distance that the ball travels before
hitting the floor.
5. To study circular motion, two students use the hand- held device
shown above; this consists of a rod on which a spring scale is
attached. A polished glass tube attached at the top serves as a
guide for a light cord attached the spring scale. A ball of mass
0.200 kg is attached to the other end of the cord. One student
swings the teal around at constant speed in a horizontal circle
with a radius of 0.500 m. Assume friction and air resistance are
negligible.
a. Explain how the students, by using a timer and the information
given above, can determine the speed of the ball as it is
revolving.
b. How much work is done by the cord in one revolution? Explain how
you arrived at your answer.
c. The speed of the ball is determined to be 3.7 m/s. Assuming that
the cord is horizontal as it swings, calculate the expected tension
in the cord.
d. The actual tension in the cord as measured by the spring scale
is 5.8 N. What is the percent difference between this measured
value of the tension and the value calculated in part c.?
e. The students find that, despite their best efforts, they cannot
swing the ball so that the cord remains exactly horizontal.
i. On the picture of the ball, draw vectors to represent the forces
acting on the ball
and identify the force that each vector represents.
ii. Explain why it is not possible for the ball to swing so that
the cord remains
exactly horizontal.
Calculate the angle that the cord makes with the horizontal.
Universal Gravity 1. During a lunar eclipse, the Moon, Earth, and
Sun all lie on the same line, with the Earth between
the Moon and the Sun. The Moon has a mass of 7.4 × 1022 kg; Earth
has a mass of 6.0 × 1024 kg; and the Sun has a mass of 2.0 × 1030
kg. The separation between the Moon and the Earth is given by 3.8 ×
108 m; the separation between the Earth and the Sun is given by 1.5
× 1011 m.
(a) Calculate the force exerted on Earth by the Moon.
(b) Calculate the force exerted on Earth by the Sun.
(c) Calculate the net force exerted on Earth by the Moon and the
Sun.
2. A 2.10-kg brass ball is transported to the Moon. (The radius of
the Moon is 1.74 × 106 m and its mass is 7.35 × 1022 kg.)
(a) Calculate the acceleration due to gravity on the Moon.
(b) Determine the mass of the brass ball on Earth and on the
Moon.
(c) Determine the weight of the brass ball on Earth.
(d) Determine the weight of the brass ball on Moon.
3. A satellite of mass m is in a circular orbit around the Earth,
which has mass Me and radius Re. Express your answers in terms of
a, m, Me, Re, and G.
(a) Write the equation that can describe the gravitational force on
the satellite.
(b) Write an equation that can be used to find the acceleration of
the satellite.
(c) Find the acceleration of the satellite when it stays on the
same orbit with the radius a. Is this acceleration greater, less
than the acceleration g on the surface of Earth?
(d) Determine the velocity of the satellite as it stays on the same
orbit.
(e) How much work is done the gravitational force to keep the
satellite on the same orbit?
(f) What is the orbital period of the satellite?
4. A satellite is placed into a circular orbit around the planet
Jupiter, which has mass MJ = 1.90 x 1027 kg and radius RJ = 7.14 x
107 m.
(a) If the radius of the orbit is R, use Newton's laws to derive an
expression for the orbital velocity.
(b) If the satellite increases its orbital radius, how it would
change the orbital velocity? Explain.
(c) If the radius of the orbit is R, use Newton’s laws to derive an
expression for the orbital period.
(d) The satellite rotation is synchronized with Jupiter’s rotation.
This requires an equatorial orbit whose period equals Jupiter’s
rotation period of 9 hr 51 min = 3.55*104 s. Find the required
orbital radius.
5. The Sojourner rover vehicle was used to explore the surface of
Mars as part of the Pathfinder mission in 1997. Use the data in the
tables below to answer the questions that follow.
Mars Data Sojourner Data Radius: 0.53 x Earth's radius Mass of
Sojourner vehicle: 11.5 kg Mass: 0.11 x Earth's mass Wheel
diameter: 0.13 m
Stored energy available: 5.4 x 105 J Power required for driving
under average conditions: 10 W
Land speed: 6.7 x 10-3 m/s
(a) Determine the acceleration due to gravity at the surface of
Mars in terms of g, the acceleration due to gravity at the surface
of Earth.
(b) Calculate Sojourner's weight on the surface of Mars.
(c) Assume that when leaving the Pathfinder spacecraft Sojourner
rolls down a ramp inclined at 20° to the horizontal. The ramp must
be lightweight but strong enough to support Sojourner. Calculate
the minimum normal force that must be supplied by the ramp.
(d) What is the net force on Sojourner as it travels across the
Martian surface at constant velocity? Justify your answer.
(e) Determine the maximum distance that Sojourner can travel on a
horizontal Martian surface using its stored energy.
(f) Suppose that 0.010% of the power for driving is expended
against atmospheric drag as Sojourner travels on the Martian
surface. Calculate the magnitude of the drag force.
Energy
1. A 50 kg block is pulled from rest by a force of 1000 N at 37°
across a horizontal rough
surface over a distance of 5.6 m. The coefficient of kinetic
friction between the block and
the surface is 0.5.
a. Draw a free-body diagram and show all the applied forces.
b. How much work is done by force F?
c. How much work is done by the normal force?
d. How much work is done by the gravitational force?
e. How much work is done by the friction force?
f. What is the net work done on the block?
g. What is the change in kinetic energy of the block?
2. A boy pushes a 10 kg sled at a constant speed by applying a
force of 75 N at 30° with
respect to the horizontal. The sled is pushed over a distance of 15
m.
a. Draw a free-body diagram and show all the applied forces.
b. How much work is done by force F?
c. How much work is done by the normal force?
d. How much work is done by the gravitational force?
e. How much work is done by the friction force?
f. What is the coefficient of kinetic friction between the sled and
the surface?
g. How much work is done by the net force on the sled?
3. A 5 kg block is released from rest at the top of a
quarter-circle type curved frictionless
surface. The radius of the curvature is 3.8 m. When the block
reaches the bottom of the
curvature it then slides on a rough horizontal surface until it
comes to rest. The
coefficient of kinetic friction on the horizontal surface is
0.02.
a. What is the kinetic energy of the block at the bottom of the
curved surface?
b. What is the speed of the block at the bottom of the curved
surface?
c. Find the stopping distance of the block?
d. Find the elapsed time of the block while it is moving on the
horizontal part of the
track.
e. How much work is done by the friction force on the block on the
horizontal part of the
track?
4. Spring gun with a spring constant K is placed at the edge of a
table which distance
above the floor is H and the apparatus is used to shoot marbles
with a certain initial
speed in horizontal. The spring is initially compressed by a
distance X and then
released. The mass of each marble is m.
a. How much work is done by the spring on the marble?
b. What is the speed of the marble at the edge of the table?
c. What is the total energy of the marble at the edge of the table
with respect to floor
level?
d. How much time it will take the marble to reach the floor level
from the table?
e. What is the horizontal range of the marble?
f. What is the kinetic energy of the marble just before it strikes
the floor?
5. A 5 kg object is initially at rest at x0 = 0. A non-constant
force is applied to the object.
The applied force as a function of position is shown on the
graph.
a. How much work is done on the object during first 12.5 m?
b. What is the change is kinetic energy at the end of 12.5 m?
c. What is the speed of the object at the end of 12.5 m?
d. What is the total work done by the force for the entire
trip?
e. What is the change in kinetic energy for the entire trip?
f. What is the speed of the object at the end of 20 m?
6. A 900 kg roller coaster car starts from rest at point A rolls
down the track and then goes
around a loop and when it leaves the loop flies off the inclined
part of the track. All the
dimensions are: H = 80 m, r = 15 m, h = 10 m, = 30.
a. What is the speed of the car at point B?
b. What is the speed of the car at point C?
c. What is the speed of the car at point D?
d. What is the force applied by the surface on the car at point
B?
e. What is the force applied by the surface on the car at point
C?
f. How far from point D will the car land?
Momentum
1. Block 1 with a mass of 500 g moves at a constant speed of 5 m/s
on a horizontal
frictionless track and collides and sticks to a stationary block 2
mass of 1.5 kg. Block 2 is
attached to an unstretched spring with a spring constant 200
N/m.
a. Determine the momentum of block 1 before the collision.
b. Determine the kinetic energy of block 1 before the
collision.
c. Determine the momentum of the system of two blocks after the
collision.
d. Determine the velocity of the system of two blocks after the
collision.
e. Determine the kinetic energy of the system two blocks after the
collision.
f. Determine the maximum compression in the spring after the
collision.
2. A 20 g piece of clay moves with a constant speed of 15 m/s. The
piece of clay collides and sticks
to a massive ball of mass 900 g suspended at the end of a
string.
a. Calculate the momentum of the piece of clay before the
collision.
b. Calculate the kinetic energy of the piece of clay before the
collision.
c. What is the momentum of two objects after the collision?
d. Calculate the velocity of the combination of two objects after
the collision.
e. Calculate the kinetic energy of the combination of two objects
after the collision.
f. Calculate the change in kinetic energy during the
collision.
g. Calculate the maximum vertical height of the combination of two
objects after the
collision.
3. A 10 g bullet moves at a constant speed of 500 m/s and collides
with a 1.5 kg wooden
block initially at rest. The surface of the table is frictionless
and 70 cm above the floor
level. After the collision the bullet becomes embedded into the
block. The bullet-block
system slides off the top of the table and strikes the floor.
a. Find the momentum of the bullet before the collision.
b. Find the kinetic energy of the bullet before the
collision.
c. Find the velocity of the bullet-block system after the
collision.
d. Find the kinetic energy of the bullet-block after the
collision.
e. Find the change in kinetic energy during the collision.
f. How much time it takes the bullet-block system to reach the
floor?
g. Find the maximum horizontal distance between the table and the
striking point on the floor.
4. Block A with a mass of m is released from the top of the curved
track of radius r. Block A
slides down the track without friction and collides inelastically
with an identical block B
initially at rest. After the collision the two blocks move distance
X to the right on the
rough horizontal part of the track with a coefficient of kinetic
friction µ.
a. What is the speed of block A just before it hits block B?
b. What is the speed of the system of two blocks after the
collision?
c. What is the kinetic energy of the system of two blocks after the
collision?
d. How much energy is lost due to the collision?
e. What is the stopping distance X of the system of two
blocks?
5. Two discs of masses m1 = 2kg and m2 = 8 kg are placed on a
horizontal frictionless
surface. Disc m1 moves at a constant speed of 8 m/s in +x direction
and disc m2 is
initially at rest. The collision of two discs is perfectly elastic
and the directions of two
velocities presented by the diagram.
a. What is the x- component of the initial momentum of disc
m1?
b. What is the y- component of the initial momentum of disc
m1?
c. What is the x- component of the initial momentum of disc
m2?
d. What is the y- component of the initial momentum of disc
m2?
e. What is the x- component of the final momentum of disc m1?
f. What is the x-component of the final momentum of disc m2?
g. What is the y-component of the final momentum of disc m2?
h. What is the final vector velocity of m2?
i. What is the y-component of the final momentum of disc m1?
j. What is the final vector velocity of disc m1?
Electrostatics
1. A charged sphere A has a charge of +9 µC and is placed at the
origin.
a. What is the electric potential at point P located 0.6 m from the
origin?
A point charge with a charge of+3 µC and mass of 5 g is brought
from infinity to point P.
b. How much work is done to bring the point charge from infinity to
point P?
c. What is the electric force between two charges?
d. What is the net electric field at point 0.3 m from the
origin?
The sphere stays fixed and point charge is released from
rest.
e. What is the speed of the point charge when it is far away from
the origin?
2. Two charges are separated by a distance of 0.5 m. Charge Q1 = -9
µC. The electric field at the
origin is zero.
a. What is the magnitude and sign of charge Q2?
b. What is the magnitude and direction of the electric force
between the charges?
c. What is the electric energy of the system of two charges?
d. What is the net electric potential at the origin?
e. How much work is required to bring a negative charge of -1 nc
from infinity to the origin?
3. A charge Q1 = +9 µC is placed on the y-axis at -3 m, and charge
Q2 = -16 µC is placed at the x-
axis at +4 m.
a. What is the magnitude of the electric force between the
charges?
b. On the diagram below show the direction of the net electric
field at the origin.
c. What is the magnitude of the net electric field at the
origin?
d. What is the electric energy of the system of two charges?
e. What is the net potential at the origin?
f. How much work is required to bring a small charge +1 nC from
infinity to the origin?
4. Four equal and positive charges +q are arranged as shown on
figure 1.
a. Calculate the net electric field at the center of square?
b. Calculate the net electric potential at the center of
square?
c. How much work is required to bring a charge q0 from infinity to
the center of square?
Two positive charges are replaced with equal negative charges,
figure 2.
d. Calculate the net electric field at the center of square.
e. Calculate the net electric potential at the center of
square.
f. How much work is required to bring a charge q0 from infinity to
the center of square?
5. In an oil-drop experiment, two parallel conducting plates are
connected to a power supply with a
constant voltage of 100 V. The separation between the plates is
0.01 m. A 4.8x10-16 kg oil drop is
suspended in the region between the plates. Use g = 10 m/s2.
a. What is the direction of the electric field between the
plates?
b. What is the magnitude of the electric field between the
plates?
c. What is the sign and magnitude of the electric charge on the oil
drop when it stays
stationary?
The mass of the drop is reduced to 3.2*10-16 kg because of
vaporization.
d. What is the acceleration of the drop?
6. A parallel-plate capacitor is connected to a battery with a
constant voltage of 120 V. Each plate
has a length of 0.1 m and they are separated by a distance of 0.05
m. An electron with an initial
velocity of 2.9*107 m/s is moving horizontally and enters the space
between the plates. Ignore
gravitation.
a. What is the direction of the electric field between the
plates?
b. Calculate the magnitude of the electric field between the
plates.
c. Describe the electron’s path when it moves between the
plates.
d. What is the direction and magnitude of its acceleration?
e. Will the electron leave the space between the plates?
Electric Current and Circuits 1. A physics student has an
assignment to make an electrical heating system with the set
of materials listed below:
a. In a space below draw a diagram showing all the elements
connected in one
electrical circuit that can provide the maximum rate of heat
produced. Use two
meters in your circuit, they will help to measure the heat
rate.
The battery has an emf of 12 V and an internal resistance of 0.5 Ω
and each heating
coil has a resistance of 17.3 Ω.
b. When the switch is closed, what is the current running through
the battery?
c. What is the terminal voltage on the battery?
d. What is the rate of energy delivered by the heating
system?
e. If the switch is closed for 5 min, what is the total energy
dissipated in the coils?
2. An electric motor in a toy car can operate when connected to a 6
V battery and has a
current of 0.5 A. A physics student wants to run the toy car but
unfortunately he could
find a 12 V battery in the physics lab. The student also found a
box with a set of five 6-Ω
resistors.
a. Use given materials design an electric circuit in which the
electric motor will operate
properly.
ii. Explain your reasoning in designing this particular
circuit.
b. Calculate the net resistance of the circuit.
c. Calculate the power dissipated in the circuit.
3. Three light bulbs are connected in the circuit show on the
diagram. Each light bulb can
develop a maximum power of 75 W when connected to a 120-V power
supply. The
circuit of three light bulbs is connected to a 120 V power
supply.
a. What is the resistance of the circuit?
b. What is the power dissipated by the circuit?
c. How would you compare this power to the power when all bulbs are
connected in
parallel?
d. What is the current in light bulb L1?
e. What is the voltage across light bulb L1?
f. What is the voltage across light bulb L2?
4. Four resistors are connected in a circuit. The circuit is
connected to a battery with emf ε
and negligible internal resistance. The current through 9.6 Ω
resistor is 0.25 A.
a. What is the net resistance of the circuit?
b. What is the voltage drop across 6- Ω resistor?
c. What is the current in 4- Ω resistor?
d. What is the emf of the battery?
e. What is the net power dissipation?
5. Five resistors are connected to a battery with an emf of 12 V
and an internal resistance
of 1 Ω.
b. Calculate the current in the battery.
c. Calculate the terminal voltage of the battery.
d. Calculate the power dissipation in the 3- Ω resistor.
e. Calculate the power dissipation in the internal
resistance.
6. Four resistors and a capacitor are connected to an 18 V battery
with negligible internal
resistance, as shown on the diagram. Initially the capacitor is
disconnected from the
battery – switch is open
Switch is closed and the current reached constant value.
d. Calculate the charge on the capacitor.
e. Calculate the energy stored in the capacitor.
Magnetism
1. A long horizontal wire carries an electric current I = 50 A.
Point P is located at a distance 2.5 mm
above the current.
a. What is the direction of the magnetic field at point P?
b. What is the magnitude of the magnetic field at point P?
A thin horizontal rod has a length L = 1 m and mass m = 50 g is
connected to a circuit. The circuit contains
a battery V = 12 V, a resistor R = 0.06 Ω, a switch, and connecting
wires. The rod is supported in horizontal
position by two light connecting wires.
c. What is the direction of the electric current in the rod?
d. On the diagram below show all the applied forces on the
rod.
e. What is the tension force in supporting wires?
2. Charged particle of mass m and charge q is released from rest in
region between two charged
plates M and L. After passing the region of the electric field with
an accelerating voltage Va the
particle enters another region filled with a magnetic field of
magnitude B and directed out of the
page.
a. What is the sign of the charge on the particle?
b. What is the velocity of the particle as it enters the magnetic
field?
c. What is the direction of the magnetic force on the
particle?
d. Describe the path of the particle in the magnetic field.
e. What is the radius of the curvature of the particle in the
magnetic field?
f. What is the direction and magnitude of the electric field that
can be used to make the path
of the particle straight?
3. An electron is accelerated by an electric field produced by two
parallel plates M and L. When the
electron enters a region filled with a magnetic field of magnitude
B = 0.5 T its velocity v = 1.6107
m/s.
a. What is the direction of the accelerating electric field between
the plates M and L?
b. What is the accelerating voltage of the electric field?
c. What is the direction of the magnetic field?
d. What is the radius of the curvature of the electron in the
magnetic field?
e. What is the direction of the deflecting electric field required
to make the electron’s path
straight?
f. What is the magnitude of the deflecting electric field?
4. In a mass spectrometer a charged particle is accelerated to a
velocity v = 5.9 107 m/s by an
electric field and allowed to enter a magnetic field B, where it is
deflected in a semi-circular path
of radius R = 10 cm. The magnetic field is uniform of magnitude B =
16 T and oriented out of the
page.
a. What is the sign of the charge on the particle?
b. What is the acceleration of the particle in the magnetic
field?
c. What is the ratio between the charge and mass of the particle
q/m?
d. What is the direction of the accelerating electric field?
e. What is the accelerating voltage of the electric field?
Electro-Magnetic Induction
1. A 0.2 Ω rectangular loop of wire has an area of 0.5 m2 and
placed in a region where
magnetic field changes as shown on the diagram.
a. What is the magnetic flux in the loop at 0.4 s?
b. What is the induced emf for the following time?
i. _______ 0.1 s ii. ________0.3 s iii. ________ 0.5 s
c. What is the induced current for the following time?
i. _______ 0.1 s ii. ________0.3 s iii. ________ 0.5 s
d. On the diagram below graph the induced current as a function of
time.
2. A rectangular loop of wire 0.5 m wide and 1.5 m long is moving
out of a uniform
magnetic field B = 2 T at a constant speed of 2m/s. The left side
of the loop stays
inside the field when the right side is out. The resistance of the
loop is 0.5 Ω.
a. What is the direction of the induced current in the loop?
b. Calculate the induced emf in the loop.
c. Calculate the induced current in the loop.
d. Calculate the applied force required to move the loop at the
constant
speed.
e. Calculate the power developed by the force.
3. A metallic rod has a length L and slides at a constant speed v
on the top of two
conducting parallel rails. The rails are connected to a resistor R.
The apparatus is
placed in a uniform magnetic field B which is perpendicular to the
plane where
rod is moving.
b. Determine the induced emf.
c. Determine the induced current in the circuit.
d. Determine the electric field E induced in the rod.
e. Determine the force required to move the rod at the constant
speed.
f. Determine the power dissipated in the resistor when the rod
crosses the
magnetic field.
4. A coil 30 cm in diameter consist of 20 turns of circular copper
wire 2 mm in
diameter. The coil is connected to a low resistance galvanometer.
Initially coil is
placed in a uniform magnetic field perpendicular to its plane.
During the
experiment the magnetic field changes from 0.5 T to 2.5 T in 0.4 s.
Ignore the
resistance of the connecting wires.(copper resistivity
1.6810-8Ωm)
a. Calculate the initial flux in the coil.
b. Calculate the induced emf in the galvanometer.
c. Calculate the induced current in the coil.
d. Calculate the power dissipated in the coil as the field
changes.
Answer Key
b. 10 to 14 s
c. 8 m
d. 28 m
e. 2.8 m/s
f. 1 m/s2, 0, -2 m/s2, 0, -1 m/s2, 0
g.
e. 56.4 mi
5. a. 2 s
Dynamics
1.
a)
(g−a)
or
FT
m2g
2.
1+ 2+
1+ 2+ )
6.
a) a(0-5s) = 0 m/s2, a(5-10s) = 5 m/s2, a(10-15s) = 0 m/s2,
a(15-20s) =-5 m/s2
b) v(0-5s) = 0 m/s, v(5-10s) = 25 m/s, v(10-15s) = 25 m/s,
v(15-20s) =0 m/s
c) x(0-5s) = 0 m, x(5-10s) = 62.5 m, x(10-15s) = 187.5 m, x(15-20s)
=250 m
T
Circular Motion
1. a. v = 15 m/s b. v = 21.1 m/s c. v = 8.5 m/s
2. a. FNET = 3 Mg; FNET is pointed downwards b. vO = √(3Lg) c. t =
2√(L/g) d. x = 2L√3
3. a.
– g))
d. Velocity is upwards, accelerati9on is g down 4. a. E = 3.63
J
b. 8.2 m/s c. i. 3.5 N ii. 9.4 N d. 1.6 m
FT FT
Calculate T =
Calculate v = 2r/T b. none, Δx = 0, also F is perpendicular to v c.
T = 5.5 N d. % difference = 5% e. i. ii. The net force in the
vertical direction must be zero. Tension must support the weight
iii. = 20O
Universal Gravity
1. a. 2.05 X 1022 N b. 3.56 x 1022 N c. 3.54 x 1022 N
2. a. 1.6 m/s2
3. a. FG =
d. v = √
b. v = √
if r increases and v decreases
c. 1.1 x 104 s r = 1.6 x 10 8 m
5. a. 0.21g b. 23.9 N c. 22.5 N d. F = 0 e. 360 m f. 4.9 N
Energy
Momentum
1. a. 2.5 kg m/s b. 6.25 J c. 2.5 kg m/s d. 1.25 m/s e. 1.56
J
f. 0.12 m 2. a. 0.3 kg m/s b. 2.25 J c. 0.3 kg m/s d. 0.33 m/s e.
0.05 J
f. -2.2 J g. 0.006 m
3. a. 5 kg m/s b. 1250 J c. 3.3 m/s d. 8.2 J e. -1241 J
f. 0.38 s g. 1.25 m
4. a. (2gr)1/2
b. (2gr)1/2/2 c. grm/2 d. –mgr/2 (half is lost) e. r/4μ
5. a. 16 kg m/s b. 0 c. 0 d. 0 e. 0
f. 16 kg m/s g. 9.2 kg m/s h. 2.3 m/s i. -9.2 kg m/s j. 4.6
m/s
Electrostatics
b. 0.4 J
c. 0.675 N
e. 12.6 m/s
b. 6.48 N; Away
3. a. 0.052 N
4. a. 0
d. 5 m/s2
6. a. Up
b. 2,400 V/m
c. Parabolic, Downward
e. It will leave the plane
Electric Current and Circuits
1. a) Heating coils in parallel, voltmeter in parallel, ammeter in
series.
b) 1.3 A
c) 11.35 V
d) 14.9 W
e) 4470 J
2. a) Two resistors in series with the motor. This reduces the
currents to the
required 0.5 A.
b) 24
c) 6 W
d) 0.42 A
e) 80 V
f) 40 V
b. 4 x 10-3 T
c. To the Right
2. a. Positive
e. Down
FB mg
T T
d. Right
Electro-Magnetic Induction
i. -1 V ii. 0 iii. 2v
c. i. 5 A ii. 0 iii. 10 A
d.
2.
a. Counter clockwise b. 2 V c. 4 A d. 4 N e. 8 W
3. a. Counter clockwise b. ξ = BLv c. I = BLv/R d. E = Bv e. F =
B2L2v/R f. P = B2L2v2/R